Funny thing. When I wrote my small stupid essay on a possible campaign, I almost hit the jackpot there. First, there would be no "Vishnans" nor any of that crap. There is no god, only death. Shivans are death, we are alone to defeat it, with no cheats, with no help. Second, there would be a rally to Shivanland. Third, Cappella would have been a black hole, and I had envisioned that either Shivans "liked" black holes, or they used them for wormholes.
What I didn't get was that it was bound to be a joint endeavour by Vasudans and Terrans. I always thought that the GTVA after Cappella was completely frustrated and depressed, without any plans to go further into the galaxy to find anything else, terrified of the star-destroyers. So it would take a rebeld to force things through and make the GTVA fight through unimagined architectures of space.
Imagine. Dyson spheres, closely to red dwarf suns, black structures that let reddish corona pass through, giant balloons of gas sucking up power. Black cities of habors, cables joining thousands of sathanas. In the void center, a black hole. Could be Cappella.